Mapping Where People Can Live Safely in a Changing Climate: The Global Habitability Index

Where can the world’s most vulnerable populations live safely and sustainably?

Across the world, rising temperatures, degraded environments and weak governance are putting pressures on communities that depend on local land, water and institutions for survival. The Climate Complexity Group at the Alliance is developing a Habitability Index to answer this question. The index combines environmental, social, and governance data to measure how well different regions can support human life. By identifying places where conditions are deteriorating, and where recovery is still possible, the tool aims to help decision-makers act before crises deepen.

Beyond Single Measures

Many global indices measure vulnerability, development or environmental health, which capture only one part of the story. Habitability and migration are not simple measures, they emerge from the complex ways ecosystems, people, and institutions interact under stress. The Habitability Index brings these dimensions together, linking data on ecosystem health, climate risks and governance to show whether a place can continue to support and sustain life as conditions change.

The Habitability Index examines three dimensions.

• First, the ecosystem condition, including terrain, rainfall, temperature, soil quality, tree cover loss and biodiversity. These factors determine whether land can support communities and livelihoods.
• Second, exposure to climate hazards such as droughts, heatwaves and pluvial floods, which directly affect people’s health, mobility and income.
• Finally, governance and conflict, which influence whether communities can adapt under pressure. Even in harsh environmental conditions, strong governance and stability make adaptation possible.

Together these elements reveal where people can live safely and where systems are close to breaking point. This approach moves beyond fixed rankings to reflect the complexity of real-world conditions, recognizing that movement can be both a sign of adaptation and a signal of distress.

Designed for Action

With over 123 million people displaced globally and climate hazards intensifying, better tools are needed to anticipate where help is needed most.

The Habitability Index is designed to support real-world decisions. It can help governments and humanitarian organizations identify areas most at risk from environmental degradation or instability, e.g. guide planning and investment by revealing where natural ecosystems are under pressure, but still recoverable, and help researchers and decision-makers map potential displacement hotspots where climate stress overlaps with limited local capacity.

The index can be scaled from global to regional, to national and sub-national levels, offering both the big picture and local insights. By connecting data across these domains, the tool supports more informed planning and anticipatory action.

Our researchers recently presented the index at the  , held at Columbia Climate School in New York. The work drew interest from researchers and practitioners seeking tools to better anticipate where people and ecosystems are most at risk.

What comes next?

The Climate Complexity Group is now refining the index and exploring how to combine it with population movement data to identify emerging habitability challenges before they become crises. A preliminary habitability index for Africa at the Administrative Level 2 (see Fig 1 below) demonstrates the framework’s potential, showing how environmental, climate, and governance pressures interact across the continent.

Our goal is to connect scientific understanding with policy action, helping decision-makers see where conditions are deteriorating and where intervention can make the greatest difference.

`Author: Brigitte Melly, Alliance of Bioversity and CIAT. Photo Credit: CIAT/AdrianaVarón

This work is carried out with support from the CGIAR Climate Action Science Program (CASP) and the CGIAR Food Frontiers and Security (FFS) Science Program. We would like to thank all funders who supported this research through their contributions to the CGIAR Trust Fund: https://www.cgiar.org/funders/